Surgical and oncological results in rectal cancer and the value of follow-up

Minna Räsänen

Research output: ThesisDoctoral ThesisCollection of Articles

Abstract

Aims: Rectal cancer, one of the most common cancers worldwide, causes significant mortality. After curative rectal cancer surgery, local recurrences (LR) are detected in 4-10% and distant metastases in 20-31% of the patients. For diagnosing recurrence, the surveillance is recommended, but the optimal frequency, length and methods are not well established. This study analysed the pattern of rectal cancer recurrence, the usefulness of surveillance and the different surveillance instruments available. Nowadays, low colorectal or coloanal anastomosis is performed whenever possible because most patients prefer anus-preserving surgery over a permanent stoma. The covering stoma is used to facilitate anastomosis healing and to protect against fatal complications. In this study, we determined the cumulative risk of and the risk factors for failure of low colorectal or coloanal anastomosis. In locally advanced rectal cancer, when the tumour has invaded the adjacent organs, a multivisceral en bloc -resection is needed. In these resections, morbidity and mortality are higher than in standard resections. An attempt is made to decrease tumour size by neoadjuvant long-course (LC) chemoradiotherapy (CRT); the goal is to achieve clear resection margins. The oncological results of multivisceral resections for rectal cancer were evaluated, as were the risk factors for LR and survival. The response to CRT seen in response magnetic resonance imaging (MRI) and the histopathology report was analysed. In addition, the usefulness of the response seen in MRI and the pathological specimen in predicting curative resection, risk of LR and survival was investigated. Neoadjuvant short-course radiotherapy (SCRT) has been reported to diminish the rate of LR. Anyhow, meticulous total mesorectal excision (TME) surgery has good local control without RT in so-called good T2-T3N0-1 tumours , and the use of SCRT has been questioned in many countries because of side-effects and uncertainty of utility. The aim of this study was to determine, whether SCRT prevents LR in pT3N1-2 patients compared with those operated on without RT. Patients and methods: A total of 952 rectal cancer patients were operated on at Helsinki University Hospital between January 2005 and June 2014. Study I comprised 481 consecutive rectal cancer patients treated with radical intention during 2005-2011. Study II comprised all patients (n= 273) operated on with anterior resection (AR) combined with low colorectal or coloanal anastomosis and covering stoma during 2005-2011. The Study III population consisted of 94 patients, operated on because of locally advanced rectal cancer by multivisceral resection between 2005 and 2013. In Study IV, 151 patients operated on because of pT3N1-2 rectal cancer during January 2005-June 2014 were included. Of these 151 patients, 57 did not have radiotherapy (RT) before the operation and 94 had received short-course RT before surgery. Data were retrospectively collected from patient records. Results: Local recurrence occurred in 8.3% and distant metastases in 23.3% of patients treated with curative intention. The median time to recurrence was 1.3 years after operation, and 75% of recurrences were diagnosed during the first two postoperative years. Recurrences were detected significantly earlier by the follow-up visits than by symptoms. All of the surveillance instruments used, were equally useful for finding recurrences. Curative re-operation was possible in 41.1% of patients with disease recurrence. The colorectal or coloanal anastomosis was switched to a permanent stoma in 23 (8.5%) of 271 patients. Protective stoma was not closed in five patients (1.8%). Total permanent stoma rate was 10.3%. The risk factors for failure of low colorectal or coloanal anastomosis were tumour location under 6 cm from anal verge, coloanal anastomosis, early anastomotic complication, anastomotic fistula, anal incontinence, and LR. After multivisceral resection, LR occurred in 10.6%. The median time for detecting a recurrence was 1.4 years (0.7-5.2). The 5-year overall survival (OS) for the whole population was 51.8% and for curatively treated patients (n=83) 59.2%; the 5-year disease-free survival (DFS) for the latter group was 64.2%. A significant risk factor for LR and survival was R1 resection. Poor or no response in post-treatment MRI predicted LR and also seemed to predict DFS in curatively treated patients. Of patients having pT3N1-2 rectal cancer, LR occurred in altogether 11.3%. The rate of LR in the surgery only group was 14% and in the RT + surgery group 9.6%. Risk factors in univariate analysis for LR were tumour location under 6 cm from anal verge, positive circumferential resection margin (CRM), tumour perforation and mucinous histology. In multivariate analysis, the risk factors were tumour location under 6 cm from anal verge and positive CRM. The short-course RT did not prevent LR. Conclusions: The most intensive follow-up should fall within two to three years for all patients treated with curative intent, and thereafter, only patients with known risk factors for recurrence should be followed. The risk of permanent stoma after low anterior resection in our study population was low, most probably due to routine use of covering stoma. Multivisceral resection is safe and has an over 50% 5-year OS and almost 90% local control. Poor response for CRT in post-treatment MRI predicts LR and seems to be associated with decreased DFS in curatively treated patients. Achievement of R0 multivisceral resection is most important concerning LR and also survival. Short-course radiotherapy did not affect LR risk in pT3N1-2 rectal cancer patients. Larger studies allowing analysis of subgroups with different T3 classes and N1 and N2 groups separately are needed to evaluate the role of short-course neoadjuvant radiotherapy in T3N+ tumours.
Original languageEnglish
Place of PublicationHelsinki
Publisher
Print ISBNs978-951-51-3078-5
Electronic ISBNs978-951-51-3079-2
Publication statusPublished - 2017
MoE publication typeG5 Doctoral dissertation (article)

Fields of Science

  • 3122 Cancers
  • 3126 Surgery, anesthesiology, intensive care, radiology

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